Health officials say a child in southern Washington state is suspected of having measles contracted from someone in the Portland-area where two cases were found.
The Oregonian/OregonLive reports Clark County Public Health officials warn that Vancouver, Washington, residents may been exposed to the virus at three retail centers in the city late last month.
Someone with the virus entered a child care center in Gresham, Oregon, resulting in a second case being identified last week.
Multnomah County health officials say there are about 40 people known to have been exposed who have not been immunized.
The virus can spread through the air when an infected person coughs or sneezes. Symptoms, which can sometimes take weeks to appear, include coughing, fever, a runny nose and rash.